Tired of gridlock? Blame congressional scorecards

Special interest groups lobbying Congress on issues ranging from abortion to the environment give grades to lawmakers every year using key votes to determine their loyalty to the cause.Once a simple publicity tool, these scorecards have become a major reason for congressional gridlock.Lawmakers who vote the wrong way too many times can lose campaign contributions or valuable endorsements. At election time, they may see a poor rating used against them in a TV ad or mailer, especially during a crucial …